Safety base for portable grandstands



July 16, 1929.

E. CHRISTOPHER SAFETY BASE FOR PORTABLE GRANDSTANDS Filed Oct. 25, 1926 Patented July 16, 1929.

UNITED. STATES 1,720,944 PATENT OFFICE.

EUGENE CHRISTOPHER, F URBANA, ILLINOIS.

SAFETY BASE FOR PORTABLE GRANDSTANDS.

Application filed October 25, 1926. Serial No. 143,872.

This invention relates to improvements in a safety base for portable grandstands, and has for one of its principal objects the provision of a portable grandstand, sometimes known as knockdown bleachers, which includes a novel and positively operating safety device to prevent collapse.

One of the important objects of this invention is to provide, in a. portable grandstand or the like, a plurality of members for ready assembling to conveniently and comfortably seat a number of people for viewing games or the like, which grandstands can be taken down when not in use, and which, when in use, will not be subject to sidewise or other displacement or collapse even under a considerableweight or even in the event of an insecure, uneven, or soggy ground support.

' Another importantobject of this invention is theprovision of a quickly assembled and disassembled base construction for a portable grandstand or the like, which will constitute an integral portion of the grandstand itself, and be so attired thereto as to be readily disposed of and packed. in a small compass when the grandstand is taken apart.

Another an d still further important object of this invention. is the use of a. novel base construction in connect-ion with a portable grandstand, which shall act to distribute any weight placed thereon or any excess strain or stress upon one or more of the members so that in the event any supporting element becomes weakened or is placed upon an insecure or uneven foundation such as spongy ground or the like, a collapse will be n evented.

Other and further important objects of the invention will be apparent from the disclosures in the accompanying drawings and following specification. I

The invention, in a preferred form, is illustrated in the drawings and hereinafter more fully described.

In the drawings:

F .gure 1 is a perspective view of a portion of a portable grandstand constructed in accordance with the principles of this invention.

Figure 2 is a detail top plan view of a portion of the supporting base.

Figure 3 is a side elevation viewed from the rear of the construction shown in Figure 2.

Figure 4 is a top plan detail view of another part of the supporting base.

Figure 5 is a side elevation of the apparatus shown in Figure 4.

As shown in the drawings The reference numerals 10 indicate generally a plurality of supporting boards or sleepcrs adapted to be laid upon the ground in the place where the portable grandstand is to be erected. lllounted in turn upon each supporting sleeper 10 is a. stringer 12 supported in any suitable manner at one end of the sleeper and estending upwardly and rearwardly at an angle of some twenty-live to forty degrees, as best shown in Figure 1.

- Supports for the stringers 12 in the form of jacks or the like 14 are provided, each com posed of two members positioned at an. angle and connected at the top, and having a notch in the top for the reception of the stringer 12. Locking means 18, in the form-of blocks or similar elements are nailed or otherwise secured to the stringers 12 and are adapted to receive the upper ends of the jacks 1 and support the same in desired relation to the stringers 12.

It is obvious that any number of supporting sleepers 10 and stringers 12 may be used in a grandstand unit together with a corresponding number of acks, and extending longitudi nally across the stringers 12 and at right anglos thereto is a plurality of planks 20 which, constitute seatboards, these seatboards being supported by extensions in the form of metal straps 22. A nun'iber of footboards 24, corresponding to the number of seatboards, but one less in number, are provided, these footboards 24; being likewise supported by metal straps or 'brackets26 extending downwardly from the stringers 1.2 and attached to the under faces thereof by means of lag screws or in any other suitable manner. The planks constituting the seats and footboards are readily removable-from the stanchions 22 and brackets 26, thereby providing for an easy and ready dismantling of the entire struc ture.

If portable grandstands such described above are placed upon filled or soft ground, or

on a slope, all of the weight will be thrown upon the legs on one side of the jacks 14 so that these legs will sink into the ground, causing the bleachers to crash or collapse sidewise. In order to guard against such a contingency and accident a plurality of jack locks 28 are provided, adapted to be placed. behind the legs of the jacks 14: these jack locks being in the form of longitudinally extending members supported in proper position on the sleepers 10 by means of jack lock irons 30 attached to the sleepers 10 and having their free ends bent upwardly and forwardly in the form of hooks 82. 111 order to provide for a positive joint betweenthe jack lock members in a long string of bleachers an angular cut is provided at the end shown at 3st in Figures 2 and t, this cut being at an angle of approximately thir y degrees in each case, so that the ends of the jack lock members may be closely fittedtogether under the books 32.

Securely attached to the under faces of the jack locking members 28 at the point where the ends of the legs of the achs l4 would ordinarily contact with the ground a plurality of blocks or tlat supports 36, thesebeing attached to the jack locks 28 by means of screws or bolts 38, and in each case extending forwardly therefrom to receive and support the foot or leg of the jack 14:. This construction is shown in perspective in Figure 1, and in detail in the remaining figures. The ends of the legs of the jacks are beveled to provide for a full bearing surface on the base member or block 36.

In Figures 2 and 3 are shown the construction at the rear of the stand where the legs 14: of the jacks practically contact with each other at their lower ends, the blocks 36 being accordingly positioned adjacent each other and adaptexl to be placed directly on the ground.

In Figures t and 5, the ends of the legs of the jacks being shorter, do not quite coinetogether at their ends, and accordingly the blocks 36 are spaced apart along the length of the jack lock 28.

As best shown in Figure 3, cleats 40 are provided on the under faces of the jack lock.

members 28 adjacent the point where the sleeper it) passes thereunder, so as to assure a proper positioning of the sleeper 10 with respect to the jack locks and also with respect to the remaining members.

It will be seen that this form of structure can be readily built up to accommodate a large number of persons, and by means of the improved base construction provided there is no possibility of any undue strain being placed upon any particular part, and therefore any resultantbreakage or collapse of the structure due to its being positioned upon soft, spongy,,or unevenground will be prevented, as the entire structure is so locked together and so adequately supported by means of the augmented area as applied to the ground, that a very vsafe foundation for a weight greatly in excess of the capacity of such a stand is provided.

I am aware that many chan m ayibe made and numerous details of construction varied throughout a wide range without departing frointhe Pltl'l'lClPlQSOlf this invention, and I therefore do not purpose limiting the patent granted hereon otherwise than as necessitated by the prior art.

I claim as my invention:

In a portable grandstand, aseries of sleepers adaptedto be placed on the ground, a cor responding number of stringers mounted on said sleepers at an angle thereto and supported at one end thereof, a plurality of jacks for supporting the stringers, said ijacks being readily removabletherefrom, a plurality of upstai'iding extending stanchions spaced along each stringer, andiseatboards on the stanchions, a plurality of dowi'iwardly extending brackets on each stringer positioned alternately with the stanchions and footboards in the brackets, and a plurality of inembersextending across the sleepers behind thelegs of the acks to maintain the jacks in desired position. together with supports for the legs of the jacks on said members, said. cross men'ibers comprising bars re novzbly mounted on the sleepers, and a pair of foot supports for each jack, each of said foot supports comprising a rectangular base board fastened} to the under side of said'locking bars and llllllQStIll'lQ plane as the sleepers,thereby adapted to be placed on the ground, certain of said base boards adapted to abut the sleepers and certain other of said base boards adapted to abut each other to prevent horizontal sliding movement.

In testimony whereof I afiix my signature.

EUGENE CHRISTOPHER. 

